Dreaming souls : sleep, dreams and the evolution of the conscious mind

What, if anything, do dreams tells us about ourselves?

What is the relationship between types of sleep and types of dreams?

Does dreaming serve any purpose? Or are dreams simply meaningless mental noise - " unmusical fingers wandering over the piano keys"?

In this survey of sleep and dreams, Flanagan argues that while sleep has a clear biological function and adaptive value, dreams are merely side effects, "free riders," irrelevant from an evolutionary point of view.

But dreams are hardly unimportant. Indeed, Flanagan argues that dreams are self-expressive, the result of our need to find or to create meaning, even when we're sleeping.